The United Nations refugee agency (UNHCR) and the International Organization for Migration (IOM) have called on U.S. President Donald Trump to continue his country's "long tradition" of offering asylum to people fleeing war and persecution.

The appeal came in a joint statement from UNHCR and IOM issued in reaction to Trump's new executive order barring Syrian refugees from the United States and suspending visits from seven predominantly Muslim countries.

Trump said the steps were part of new measures to "keep radical Islamic terrorists" out of the United States.

"The needs of refugees and migrants worldwide have never been greater and the U.S. resettlement program is one of the most important in the world," the two Geneva-based UN agencies said in their joint January 28 statement.

The UN agencies added that the U.S. policy of welcoming refugees "has saved the lives of some of the most vulnerable people in the world who have in turn enriched and strengthened their new societies."

The agencies said they hoped "that the U.S. will continue its strong leadership role and long tradition of protecting those who are fleeing conflict and persecution."

Some 25,000 refugees were resettled in the United States between October and year-end under the UNHCR's program for the most vulnerable, the agency said last week.